Even though it's still too early to plant tomatoes, it's not too early to make plans for supporting those plants.
If you're growing the dwarf, patio tomatoes, then little support is needed as these plants only grow a few feet tall. But for determinate varieties, such as 'Celebrity', and indeterminate varieties, such as most heirloom tomatoes and cherry tomatoes, you'll need a hefty support structure. Large tomato plants will flop down, making the leaves more susceptible to diseases and fruits more likely to rot or be eaten by animals.
One traditional method is to stake the plants. This works fine on determinate varieties that stand less than 4 feet tall. But you'll need to remove suckers and use Velcro brand plant ties to attach the main stem to the stake to keep the plants manageable. For larger indeterminate varieties that can grow 6 feet tall and very bushy, a cage or a trellis system is best.
Commercial tomato cages usually aren't large and strong enough to support these big varieties. It's best to make a wire cage from 6 foot tall deer fencing, use a sturdy 7 foot tall stake attached to help hold the cage upright, and stake the cage with tent stakes. This makes it less likely the cage will topple over in a storm.
You can also create a teepee system with A-frame supports on either side of the row, a horizontal pole attached across anchored to the A-frames and string hung down from the horizontal pole attached to the tomato branches keeping them vertical. You can use as many strings as you need.
